Service contracts and normal dll

I think their syntax and flow are similar, what stole ideas from the other ?

Also, SOAP and REST I read their differences on websites (google) but i don't know what they are exactly. could someone please picture or summarize them both for beginer level ?

can you point me to a simple hello world application that uses SOAP and another that demonstrate REST ?

Still your question is not clear. anyway the following application .demonstratre Hallo World .

Code:

---

class HelloWorld
{
        public static void Main()
        {
                System.Console.WriteLine("Hello World");
        }               
}

---